CD133^+ gallbladder carcinoma cells exhibit self-renewal ability and tumorigenicity

AIM： To identify cancer stern cells （CSCs） in human gallbladder carcinomas （GBCs）. METHODS： Primary GBC cells were cultured under serum-free conditions to produce floating spheres. The stem-cell properties of the sphere-forming cells, including self-renewal, differentiation potential, chemoresistance and tumorigenicity, were determined in vitro or in vivo. Cell surface expression of CD133 was investigated in primary tumors and in spheroid cells using flow cytometry. The sphere-colony-formation ability and tumorigenicity of CD133＋ cells were assayed.floating spheroids were generated from primary GBC cells, and these sphere-forming cells could generate new progeny spheroids in serum-free media. Spheroid cells were differentiated under serum-containing conditions with downregulation of the stem cell markers Oct-4, Nanog, and nestin （P 〈 0.05）. The differentiated cells showed lower spheroid-colony-formation ability than the original spheroid cells （P 〈 0.05）. Spheroid ceils were more resistant to chemotherapeutic reagents than the congenetic adherent cells （P 〈 0.05）. Flow cytometry showed enriched CD133＋ population in sphereforming cells （P 〈 0.05）. CD133＋ cells possessed high colony-formation ability than the CD133 population （P 〈 0.01）. CD133＋ cells injected into nude mice revealed higher tumorigenicity than their antigen-negative counterparts （P 〈 0.05）. CONCLUSION： CD133 may be a cell surface marker for CSCs in GBC.

Overexpression of p42.3 promotes cell growth and tumorigenicity in hepatocellular carcinoma

AIM:To investigate the association of p42.3 expression with clinicopathological characteristics and the biological function of p42.3 in human hepatocellular carcinoma(HCC).METHODS:We used reverse transcription-polymerase chain reaction(RT-PCR),quantitative real-time RT-PCR and western blotting to detect p42.3 mRNA and protein expression in hepatic cell lines.We examined primary HCC samples and matched adjacent normal tissue by immunohistochemistry to investigate the correlation between p42.3 expression and clinicopathological features.HepG2 cells were transfected with a pIRES2EGFP-p42.3 expression vector to examine the function of the p42.3 gene.Transfected cells were analyzed for their viability and malignant transformation abilities by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay,colony formation assay,and tumorigenicity assay in nude mice.RESULTS:p42.3 is differentially expressed in primary HCC tumors and cell lines.Approximately 69.6%(96/138) of cells were p42.3-positive in hepatic tumor tissues,while 30.7%(35/114) were p42.3-positive in tumor-adjacent normal tissues.Clinicopathological characteristics of the HCC specimens revealed a significant correlation between p42.3 expression and tumor differentiation(P = 0.031).However,p42.3 positivity was not related to tumor tumor-node-metastasis classification,hepatitis B virus status,or hepatoma type.Regarding p42.3 overexpression in stably transfected HepG2 cells,we discovered significant enhancement of cancer cell growth and colony formation in vitro,and significantly enhanced tumorigenicity in nude mice.Western blot analysis of cell cycle proteins revealed that enhanced p42.3 levels promote upregulation of proliferating cell nuclear antigen,cyclin B1 and mitotic arrest deficient 2.CONCLUSION:p42.3 promotes tumorigenicity and tumor growth in HCC and may be a potential target for future clinical cancer therapeutics.

Serum soluble suppression of tumorigenicity 2 as a novel inflammatory marker predicts the severity of acute pancreatitis

BACKGROUND Acute pancreatitis(AP)is an inflammatory disease in which the regulatory pathway is complex and not well understood.Soluble suppression of tumorigenicity 2(sST2)protein receptor functions as a decoy receptor for interleukin(IL)-33 to prevent IL-33/suppression of tumorigenicity 2L(ST2L)-pathwaymediated T helper(Th)2 immune responses.AIM To investigate the role of sST2 in AP.METHODS We assessed the association between sST2 and severity of AP in 123 patients enrolled in this study.The serum levels of sST2,C-reactive protein(CRP)and Th1-and Th2-related cytokines,including interferon(IFN)-γ,tumor necrosis factor(TNF)-α,IL-2,IL-4,IL-5 and IL-13,were measured by highly sensitive ELISA,and the severity of AP in patients was evaluated by the 2012 Atlanta Classification Criteria.RESULTS Serum sST2 levels were significantly increased in AP patients,and further,these levels were significantly elevated in severe AP(SAP)patients compared to moderately severe AP(MSAP)and mild AP(MAP)patients.Logistic regression showed sST2 was a predictor of SAP[odds ratio(OR):1.003(1.001–1.006),P=0.000].sST2 cutoff point was 1190 pg/mL,and sST2 above this cutoff was associated with SAP.sST2 was also a predictor of any organ failure and mortality during AP[OR:1.006(1.003–1.009),P=0.000,OR:1.002(1.001–1.004),P=0.012,respectively].Additionally,the Th1-related cytokines IFN-γand TNF-αin the SAP group were higher and the Th2-related cytokine IL-4 in the SAP group was significantly lower than those in MSAP and MAP groups.CONCLUSION sST2 may be used as a novel inflammatory marker in predicting AP severity and may regulate the function and differentiation of IL-33/ST2-mediated Th1 and Th2 Lymphocytes in AP homeostasis.

A meta-analysis of soluble suppression of tumorigenicity 2 （sST2） and clinical outcomes in pulmonary hypertension

Suppression of Tumorigenicity 2 （ST2） is a member of the interleukin （IL）-1 receptor family The ST2 receptor exists in two isoforms - ST2 ligand （ST2L） and soluble ST2 （sST2）.ST2L is a membrane receptor and sST2 is a trun- cated receptor which is soluble in the blood, allowing it to be detected in serum. IL-33 is a member of the IL-1 family of ligand and is the fimctional ligand of ST2L receptor. It binds to the ST2L, thereby mediating its immune function.

Differentiation and tumorigenicity of neural stem cells from human cord blood mesenchymal stem cells

BACKGROUND： Mesenchymal stem cells （MSCs） are capable of differentiating into a variety of tissues and exhibit low immunogenicity. OBJECTIVE： To investigate isolation and in vitro cultivation methods of human cord blood MSCs, to observe expression of neural stem cell （NSC） marker mRNA under induction, and to detect tumorigenicity in animals. DESIGN, TIME AND SETTING： A cell biological, in vitro trial and a randomized, controlled, in vivo experiment were performed at the Department of Neurology, Daping Hospital at the Third Military Medical University of Chinese PLA from August 2006 to May 2008. MATERIALS： Umbilical cord blood was collected from full-term-delivery fetus at the Department of Gynecology and Obstetrics of Daping Hospital, China. Eighteen BALB/C nu/nu nude mice were randomly assigned to three groups： back subcutaneous, cervical subcutaneous, and control, with 6 mice in each group. METHODS： Monocytes were isolated from heparinized human cord blood samples by density gradient centrifugation and then adherent cultivated in vitro to obtain MSC clones. After the cord blood MSCs were cultured for 7 days with nerve growth factor and retinoic acid to induce differentiation into NSCs, the cells （adjusted density of 1 × 10^7/mL） were prepared into cell suspension. In the back subcutaneous and cervical subcutaneous groups, nude mice were hypodermically injected with a 0.5-mL cell suspension into the back and cervical regions, respectively. In the control group, nude mice received a subcutaneous injection of 0.5 mL physiological saline into the back or cervical regions, respectively. MAIN OUTCOME MEASURES： Cellular morphology was observed by inverted microscopy, cultured cord blood MSCs were examined by flow cytometry, expression of nestin and musashi-1 mRNA was detected by reverse-transcriptase polymerase chain reaction prior to and after induction, and tumorigenicity following cord blood MSC transplantation was assayed by hematoxylin-eosin staining. RESULTS： Following adherent cultivation, the majority of cord blood monocytes became rhombic and strongly expressed CD29, but not CD34, CD1 la, or CD11 b. These results supported previously known characteristics of cord blood MSCs. Following differentiation induction, nestin and musashi-1 were expressed on the surface of NSCs, exhibiting strongest expression at 48 hours, and subsequently reducing expression. Cultured cord blood MSCs were not tumorigenic in the nude mice. Cellular morphology displayed no malignant changes between the control and subcutaneous groups. CONCLUSION： MSCs can be isolated from human cord blood, efficiently expanded under culture conditions, differentiated into NSCs following induction, and display no tumorigenicity in nude mice.

Antisense Oligonucleotide Targeting TGF-β1 Abrogates Tumorigenicity of Rhabdomyosarcoma in vivo

OBJECTIVE Over-expression of transforming growth factor β1 （TGF-β1） has been observed in many advanced cancers. The present study was aimed at developing potential antisense oligonucleotides （ASONs） to repress TGF-β1 expression in rhabdomyosarcoma （RMS） RD cells, and to examine their effect on tumorigenicity of RD cells in vivo. METHODS ASONs targeting the region surrounding the start codon of TGF-β1 were synthesized and transferred into cells in the form of complexes with Lipofectamine 2000. The TGF-β1 protein was determined by immunofluorescence and ELISA. The cell viability and cell cycle were examined by MTT and flow cytometry. The RD cells, with or without TGF-β1ASON, in 50 μl of serum-free EMDM medium were injected subcutaneously into the right flank of nude mice. The tumors were then measured and weighed. RESULTS The ASON sequence targeting the first start site at bases 841-855 of the human TGF-β1 gene had the greatest effect on attenuating the expression of TGF-β1 （P 〈 0.05）. The ASONs induced a decrease in OD values after 6 d （P 〈 0.05）. Analysis of the cell cycle revealed that the ASON induced a significant decrease in cells in the S phase and an increase in cells in the G1 phase （P 〈 0,05）. In the nude mice model, the mean tumor volume, after 2 weeks of treatment with Lipofectamine or ASON, decreased to 88.5% or 55% respectively, compared to the control tumor size, resulting in a significant difference （P 〈 0.01）. CONCLUSION The sequence of the ASON, which targeted the start condon at the bases 841-855 of the human TGF-β1 gene, was demonstrated to be a useful agent for studying the regulation of TGF-β1 over-expression in RD cells, and has important therapeutic potential for suppressing the tumorigenicity of human RMS in vivo.

REDUCED TUMORIGENICITY OF METASTATIC HUMAN LUNG CANCER CELL SUBLINE（PGCL3） TRANSFECTED WITH hRARβ GENE

The recombinant PSG5-RARβ plasmid and the G418-resistant PSV2neo Plasmid ( 10 : 1) were cotransfected into PGCL3 cells by copreciprtation with calcium phosphate. The transfectants CR3 and CR4, which expressed the RARβ gene. were identified by Northern blot hybridization. The results showed that the in vitro growth and invasion of CR3 and CR4 were dramatically reduced compared to the control-transfected cell (CSV1). Furthermore, the colony-forming abilities in soft agar and the tumorigenicrty in nude mice of CR3 and CR4 were abrogated. Our results suggests that RARβ functions not only as a receptor mediating the RA action, but also as a suppressor in lung tumorigenesis.

Inhibition of cervical cancer cell proliferation and cervical tumorigenicity caused by farnesoid X receptor activation or over-expression is related to CDKN2A-p14^(ARF)-MDM2-p53 pathway

OBJECTIVE Cervical cancer is the third most malignant tumor in the world.Farnesoid X receptor(FXR) is a member of nuclear receptor superfamily.It is highly expressed in liver,kidney and small intestine,while it showed low expression level in other tissues.It not only plays an important role in the metabolism of bile acids and sugars,but also in the production of chronic inflammation in the early stage of cancer,the proliferation and migration of tumor.Compared with the normal tissue,the expression of FXR in most tumor tissues decreased.But there is no correlation between cervical cancer and FXR.So we aimed to find out the relationship between FXR and cervical cancer.METHODS A clinical study using q PCR,western blot and immunohistochemistry detected the expression of FXR in tumor tissues and normal tissues of clinical patients.FXR was activated by agonists or over-expressed by lentivirus.MTT,clone formation and flow cytometry were used to detect the relationship between FXR and proliferation of cervical cell lines.Tumor growth ability of FXR was detected by nude mice tumorigenicity.The interaction between FXR and CDKN2A-p14^(ARF)-MDM2-p53 pathway was detected by q PCR,Western blot and immunohistochemistry.RESULTS FXR was decreased in cancer tissues compared to normal control.Activation of FXR by agonist or constitutively-over-expression of FXR inhibited cervical cell proliferation.Over-expressed FXR attenuated Caski,Hela and Siha xenograft tumor growth in nude mice compared with control.Over-expression of FXR caused G1 cell-cycle arresting and up-regulated CDKN2A-p14^(ARF)-MDM2-p53 pathway.CONCLUSION FXR inhibits cervical cancer cell proliferation and cervical tumorigenicity which is related to CDKN2A-p14^(ARF)-MDM2-p53 pathway.Activation or overexpression of FXR may be a potential target for the treatment of cervical cancer.

Further Report on Carcinogenesis or Tumorigenicity ofMDCK Canine Kidney Cell(CKC) Lines and Analysis ofTheir Chromosome Karyotypes

Using Hela cell cultures as positive control and primary canine kidney cell (CKC) or feline kidney cell (FKC) cultures purified in vitro on passage 3 as negative control, the tumorigenicity of Madin-Darby canine kidney (MDCK) cells was tested in >273 nude mice, and colony formation in soft agarose and haemag-glutination under different concentration of plant lectins of these cells were carried out at the same time. Subsequently, very low tumorigenicity strains of MDCK line were successfully selected; these were evaluated for the production of canine or feline combination viral vaccines, free of infectious agents, and of known cytoge-netic and tumorigenic. It is thus evident that MDCK cell of M, JB, JC, WB or H strain can be approved as substrate for the preparation of attenuated viral vaccines, but MDCK cell of YA, YB and KA strains can not be approved as substrate for the preparation of attenuated viral vaccines. The heritable character of these cell sub-lines is comparatively stable, and shows little significant difference between passages.

Paradoxical role of interleukin-33/suppressor of tumorigenicity 2 in colorectal carcinogenesis: Progress and therapeutic potential

Colorectal cancer(CRC)is presently the second most prevalent global mortalityinducing cancer.CRC carcinogenesis is a multifactorial process involving internal genetic mutations and the external environment.In addition,non-neoplastic cell activities within tumor microenvironments for CRC development have been established.However,interleukin(IL)-33,secreted by such cell types,plays a pivotal role in cancer progression due to interaction with cellular constituents within the tumor-inflammation microenvironment.IL-33 belongs to the IL-1 cytokine family and acts as binding attachments for the suppressor of tumorigenicity(ST)2 receptor.Therefore,how to coordinate tumor microenvironment,design and optimize treatment strategies suitable for CRC,based on IL-33/ST2 signal is a challenge.Even though it has established influences upon immunitylinked conditions,IL-33 effects on CRC progression and prevention and related mechanisms are still controversial.Our review depicts controversial activities for IL-33/ST2 within carcinogenesis and cancer prevention.Moreover,IL-33/ST2 signaling is a potential therapeutic target for CRC.

Glypican 4 down-regulation in pluripotent stem cells as a potential strategy to improve differentiation and to impair tumorigenicity of cell transplants

Recent advances in stem cell technologies have opened new avenues for the treatment of a number of diseases still lacking effective therapeutic options.Cell transplantation has emerged as among the most promising clinical intervention for disorders such as injuries,diabetes,liver diseases, neurodegeneration and heart failure （Lee et al., 2013; Forbes and Rosenthal, 2014; Tabar and Studer, 2014）.

In vitro proliferation and in vivo tumorigenicity of IL-2 gene and IL-3 gene co-transfected leukemia cells

<Abstract>In vitro proliferation and in vivo tumorigenicity of IL-2 and/or IL-3 gene transfected FBL-3erythroleukemia cells were observed to investigate the anti-tumor effect of tumor vaccine. Methods: Leukemiacells were trans fected with IL-2 and/or IL-3 adenovlrus vector. The cytokine expressions were assayed, and the growth characteristics of the transfected FBL-3 cells were studied. Results: High levels of secreted IL-2 and IL-3remained for one week after transfection, and the trans fected leukemia cells became unchanged in growth in vitro and showed weak tumorigenicity in vlvo. The tumorigenicity of FBL-3 cells decreased more significantly when FBL-3 cells were transfected with both IL-2 gene and IL-3 gene than when FBL-3 cells were tran fected with IL-2or IL-3 gene only. The tumor growth was significantly delayed and survival time of the trans fected FBL-3 inoculat ed mice was significantly prolonged. Conclusion: The inhibition of tumor growth is most likely dependent on immune response induced by

Establishment and characterization of a canine chondrosarcoma cell line:Mango

In the global progress of bone tumor research,established stable and long-lasting transgenic chondrosarcoma(CSA)cell lines are rare,mainly of murine and human origin,while the establishment of canine CSA cell lines has yet to be reported.This study established a canine CSA cell line to facilitate the basic clinical study of canine CSA.Fifty fve cases of canine osteolytic disease were collected,and more than 10 bone tumor samples from dogs with typical clinical signs were used for primary cell culture.A cell line with stable passaging for more than 100 generations and mouse tumorigenic ability was successfully cultured.According to the clinical characteristics of the dog and the histopathological results of the primary tumor,CSA was diagnosed,and the CSA cell line was designated Mango.Immunohistochemical(IHC)results showed that the immunoreactivity of bone gamma-carboxyglutamate protein(BGLAP),secreted protein acidic and rich in cysteine(SPARC),alkaline phosphatase(ALPL),vimentin(VIM)and S100 were positive.However,the immunoreactivity of pan-cytokeratin(PCK),chromogranin A(CGA),and platelet endothelial cell adhesion molecule-1(CD31)was negative.Immunofuorescence(IF)results showed that the protein expressions in the Mango cell line were consistent with the IHC identifcation of the primary tumor.The Mango cell line’s doubling time was 43.92 h,and the cell formation rate exceeded 20%.There were abnormal chromosome numbers,hetero staining with toluidine blue,and certain calcifcation abilities.It could be passaged stably and continuously without changing the cell morphology and characteristics.In vivo,the cells were successfully injected into the nude mice model with a tumorigenic rate of 100%.The immunophenotype of the xenograft tumor was consistent with that of the primary tumor.Therefore,we efectively established a canine CSA cell line.As a promising cell material,this cell line can be used to construct a tumor-bearing model conducive to the subsequent basic research of canine CSA.Moreover,because of its similarity to human CSA,the animal model of CSA is also indispensable for investigating human CSA.

TGFβ signaling hyperactivation-induced tumorigenicity during the derivation of neural progenitors from mouse ESCs

Clinical therapies of pluripotent stem cells （PSCs）-based transplantation have been hindered by frequent development of terato- mas or tumors in animal models and clinical patients. Therefore, clarifying the mechanism of carcinogenesis in stem cell therapy is of great importance for reducing the risk of tumorigenicity. Here we differentiate Oct4-GFP mouse embryonic stem cells （mESCs） into neural progenitor cells （NPCs） and find that a minority of Oct4＋ cells are continuously sustained at Oct4＋ state. These cells can be enriched and proliferated in a standard ESC medium. Interestingly, the differentiation potential of these enriched cells is tightly restricted with much higher tumorigenic activity, which are thus defined as differentiation-resistant ESCs （DR-ESCs）. Transcriptomic and epigenomic analyses show that DR-ESCs are characterized by primordial germ cell-like gene sig- natures （Dazl, Rec8, Stro8, BUmp1, etc.） and specific epigenetic patterns distinct from mESCs. Moreover, the DR-ESCs possess germ cell potential to generate Sycp3＋ haploid cells and are able to reside in sperm-free spermaduct induced by busulfan. Finally, we find that TGFβ signaling is overactivated in DR-ESCs, and inhibition of TGFβ signaling eliminates the tumorigenicity of mESC-derived NPCs by inducing the full differentiation of DR-ESCs. These data demonstrate that these TGFβ-hyperactivated germ ceU-like DR-ESCs are the main contributor for the tumorigenicity of ESCs-derived target cell therapy and that inhibition of TGFβ signaling in ESC-derived NPC transplantation could drastically reduce the risk of tumor development. Keywords： embryonic stem cells, differentiation-resistant ESCs, tumorigenicity, germ cell, TGFβ signaling

The unsulfated extracellular N-terminus of vGPCR reduces the tumorigenicity of hGRO-α in nude mice

The Kaposi's Sarcoma-associated Herpesvirus (KSHV)-encoded G-protein coupled receptor (vGPCR) is an oncoprotein that is implicated in KSHV-associated malignancies. We previously revealed vGPCR incorporates sulfate groups within its extracellular N-terminal tyrosine residues (Y26 and Y28) and that this tyrosine sulfation is crucial for its tumorigenicity in nude mice. hGRO-binds vGPCR in a sulfotyrosine-dependent manner and promotes its tumorigenicity through autocrine signaling. Interestingly, an unsulfated vGPCR mutant (yydd-vGPCR) attenuated the tumor growth triggered by hGRO-α . In this study, the extracellular N-terminus of vGPCR (wt-vGN) and an unsulfated vGPCR mutant (yydd-vGN) were individually secreted, expressed and purified. A radioactive labeling assay demonstrated that wt-vGN but not yydd-vGN incorporated [ 35 S]-sulfate. In nude mice, NIH3T3 cells expressing yydd-vGN but not wt-vGN could significantly inhibit the tumor growth triggered by hGRO-α . All our data support the conclusion that the unsulfated extracellular N-terminus of vGPCR reduces the tumorigenicity of hGRO-α .

Long-term stable expression of antisense cDNA of cyclin B1 profoundly inhibits the proliferation of tumor cells and suppresses tumorigenicity in implanted mice

Background Cyclin B1 （CLB1） is necessary for mitotic initiation in mammalian cells and plays important roles in cancer development. Therefore, a potential strategy in cancer therapy is to suppress the activity of CLB1 by delivering antisense constructs of CLB1 into tumor cells. In previous CLB1 studies, antisense constructs with a short half life were often used and these constructs might not persistently inhibit CLB1. Methods We successfully created a recombinant plasmid encoding the full-length antisense cDNA of mouse cyclin B1 （AS-mCLB1） and transfected this construct to the murine Lewis lung carcinoma （LL/2） and CT-26 colon carcinoma （CT-26） cells. We isolated clones of LL/2 and CT-26 transfectants with stable expression of AS-mCLB1. Reverse transcriptional polymerase chain reaction （RT-PCR） and Western blot were applied to detect the expression of the mRNA and protein levels of CLB1. To further test the efficacy of this strategy in vivo, AS-mCLBl-expressing LL/2 and CT-26 transfectants were implanted into mice. Results We found the expression of the mRNA and protein levels of CLB1 decrease in these transfectants. The inhibition of CLB1 caused prominent G1 arrest, abnormal morphology, retarded cell growth and an increase in apoptosis. In AS-mCLBl-expressing LL/2 and CT-26 transfectants implanted mice, tumorigenicity was effectively suppressed compared with the controls. In addition, the expression of AS-mCLB1 also significantly increases the survival duration of implanted animals. Conclusion AS-mCLB1 is likely to be useful in future cancer therapy, which may be associated with its ability to down-regulate the expression of CLB1 and then induce G1 arrest and apoptosis in tumor cells.

Cyclophilin A binds to AKT1 and facilitates the tumorigenicity of Epstein-Barr virus by mediating the activation of AKT/mTOR/NF-κB positive feedback loop

The AKT/mTOR and NF-κB signalings are crucial pathways activated in cancers including nasopharyngeal carcinoma(NPC), which is prevalent in southern China and closely related to Epstein-Barr virus(EBV) infection.How these master pathways are persistently activated in EBV-associated NPC remains to be investigated. Here we demonstrated that EBV-encoded latent membrane protein 1(LMP1) promoted cyclophilin A(CYPA) expression through the activation of NF-κB. The depletion of CYPA suppressed cell proliferation and facilitated apoptosis.CYPA was able to bind to AKT1, thus activating AKT/mTOR/NF-κB signaling cascade. Moreover, the use of mTOR inhibitor, rapamycin, subverted the activation of the positive feedback loop, NF-κB/CYPA/AKT/mTOR. It is reasonable that LMP1 expression derived from initial viral infection is enough to assure the constant potentiation of AKT/mTOR and NF-κB signalings. This may partly explain the fact that EBV serves as a tumor-promoting factor with minimal expression of the viral oncoprotein LMP1 in malignancies. Our findings provide new insight into the understanding of causative role of EBV in tumorigenicity during latent infection.

Tumorigenicity risk of iPSCs in vivo:nip it in the bud

In 2006,Takahashi and Yamanaka first created induced pluripotent stem cells from mouse fibroblasts via the retroviral introduction of genes encoding the transcription factors Oct3/4,Sox2,Klf44,and c-Myc.Since then,the future clinical application of somatic cell reprogramming technology has become an attractive research topic in the field of regenerative medicine.Of note,considerable interest has been placed in circumventing ethical issues linked to embryonic stem cell research.However,tumorigenicity,immunogenicity,and heterogeneity may hamper attempts to deploy this technology therapeutically.This review highlights the progress aimed at reducing induced pluripotent stem cells tumorigenicity risk and howto assess the safety of induced pluripotent stem cells cell therapy products.

Malignant Transformation and Abnormal Expression of Eukaryotic Initiation Factor in Bronchial Epithelial Cells Induced by Cadmium Chloride

Objective To analyze the relationship between malignant transformation and abnormal expression of eukaryotic initiation factor 3 （eIF3 p36） in human bronchial epithelial （16HBE） cells induced by cadmium chloride （CdCl2）. Methods 16HBE cells were treated several times with different concentrations of CdCl2. Tumorigenic potential of transformed cells was identified by assays for anchorage-independent growth in soft agar and for tumorigenicity in nude mice after the 35th passage. Total RNA was isolated from 16HBE cells induced by CdC12, including non-transformed, Cd-transformed, and Cd-tumorigenic cell lines. Special primers for eIF3 p36 were designed and the expression of eIF3 mRNA in different cell lines was detected with fluorescent quantitative-polymerase chain reaction technique （FQ-PCR）. Results The 35th passage of 16HBE cells transformed by CdCl2 exhibited overlapping growth. Compared with the non-transformed cells, colonies of transformed cell lines in soft agar showed statistically significant increases and dose-dependent effects （P〈0.01）. All Cd-induced transformed cell lines formed rumors in nude mice within 2 weeks of inoculation, but none of the mice injected with non-transformed cells showed tumors even after 3 weeks. All tumors were pathologically identified as poorly differentiated squamous cell carcinoma. The eIF3 p36 genes in different stages of 16HBE cells transformed by CdCl2 were elevated as compared with the non-transformed control （P〈0.01）, and the eIF3 expression increased with the degree of cell malignancy. Conclusion CdCl2 is capable of inducing morphological transformation in 16HBE cells and transformed cells are potentially tumorigenic. Over-expression of eIF3 p36 is positively correlated with malignant transformation of 16HBE cells induced by CdCl2 and may be one of the molecular mechanisms potentially responsible for carcinogenesis due to Cd.

What we know about ST13, a co-factor of heat shock protein, or a tumor suppressor?

This article is to summarize the molecular and functional analysis of the gene “suppression of tumorigenicity 13” (ST13). ST13 is in fact the gene encoding Hsp70 interacting protein (Hip), a co-factor (co-chaperone) of the 70-kDa heat shock proteins (Hsc/Hsp70). By collaborating with other positive co-factors such as Hsp40 and the Hsp70-Hsp90 organizing protein (Hop), or competing with negative co-factors such as Bcl2-associated athanogen 1 (Bag1), Hip facilitates may facilitate the chaperone function of Hsc/Hsp70 in protein folding and repair, and in controlling the activity of regulatory proteins such as steroid receptors and regulators of proliferation or apoptosis. Although the nomenclature of ST13 implies a role in the suppression of tumorigenicity (ST), to date available experimental data are not sufficient to support its role in cancer development, except for the possible down-regulation of ST13 in gastric and colorectal cancers. Further investigation of this gene at the physiological level would benefit our understanding of diseases such as endocrinological disorders, cancer, and neurodegeneration commonly associated with protein misfolding.